1. Field of the Invention
The present invention relates to a multilayer coil device in which coils including conductive patterns are disposed inside a multilayer body of a lamination of insulating layers and to an antenna module and wireless communication module including the multilayer coil device.
2. Description of the Related Art
Various multilayer electronic components in which circuit elements are formed inside multilayer bodies by forming conductive patterns inside the multilayer bodies have been contemplated. One example is a multilayer electronic component described in Japanese Unexamined Patent Application Publication No. 2002-280218. The multilayer electronic component is configured such that a plurality of coils are incorporated by forming a plurality of conductive patterns in a spiral shape inside the multilayer body.
In the multilayer electronic component described in Japanese Unexamined Patent Application Publication No. 2002-280218, the plurality of coil conductive patterns are disposed on the same layer (same plane). Internal ground conductors are arranged between the plurality of coil conductive patterns. This configuration reduces the coupling between the plurality of coils adjacent to each other in the single multilayer electronic component.
However, in the known multilayer electronic component incorporating the coils described in Japanese Unexamined Patent Application Publication No. 2002-280218, as the area of the multilayer electronic component as seen in plan view, at least the sum of an area of the plurality of coil conductive patterns, the area of internal ground conductors arranged between the plurality of coil conductive patterns, and the area of portions for separating these conductive patterns is needed. Accordingly, it is difficult to decrease the area of the multilayer electronic component as seen in plan view.